Effect of SnO2 on the photocatalytical properties of TiO2 films

TiO2/SnO2 thin films with different tin atomic percentages were successfully prepared on glass substrates by the spray pyrolysis method from an alcoholic solution of TiO[C5H7O2]2 with different concentrations of SnCl4. The TiO2/SnO2 thin films prepared at 450 °C presented the anatase phase in polycrystalline configuration from %Sn = 0 in the starting solution up to %Sn = 20, at higher tin content the films present an amorphous configuration. The resulting thin films have a homogeneous surface structure with some porosity. The photocatalytical properties of the films were evaluated with the degradation of methylene blue. The products of the degradation reaction were identified by 1H nuclear magnetic resonance and the film properties were studied by atomic force microscopy, scanning electron microscopy, UV-Vis spectroscopy, and X-ray diffraction.